显微手术治疗脑胶质瘤的临床研究

目的探讨显微手术治疗脑胶质瘤的临床疗效。方法回顾性分析90例脑胶质瘤病例,依据CT、MR片测量结果行显微外科肿瘤切除术。结果90例脑胶质瘤患者中,肿瘤全切除73例（81．1％）,次全切除11例（12．2％）,大部切除6例（6．7％）。术后随访能正常工作及生活48例（51．2％）,生活能自理17例（19．8％）,生活不能自理8例（9．3％）,复发12例（14．0％）,死亡5例（5．8％）。结论采用显微手术治疗脑胶质瘤,具有切除率高,脑组织损伤小,术后恢复良好等优点,能显著提高病人生活质量,值得临床推广。     

Mitochondrial localization of P2Y1, P2Y2 and P2Y12 receptors in rat astrocytes and glioma C6 cells

We have previously shown that P2Y1, P2Y2 and P2Y12 nucleotide receptors are functionally expressed and active on the cell surface of rat glioma C6 cells. In the present study, we have immunocytochemically shown their sub-cellular colocalization with mitochondria in these cells. The same colocalization of above receptors has been found in rat astrocytes. Additionally, differences in intracellular distribution of examined receptors between both cell lines have been observed. This data indicates that P2Y1, P2Y2 and P2Y12 receptor proteins exist within mitochondria of astrocytes and C6 cells, although their role in these sub-cellular structures remains unclear.     

CD81, a cell cycle regulator, is a novel target for histone deacetylase inhibition in glioma cells

Recent advances in cancer cell biology have focused on histone deacetylase inhibitors (HDACi's) because they target pathways critical to the development and progression of disease. In particular, HDACi's can induce expression of epigenetically silenced genes that promote growth arrest, differentiation and cell death. In glioma cells, one such repressed gene is the tetraspanin CD81, which regulates cytostasis in various cell lines and in astrocytes, the major cellular component of gliomas. Our studies show that HDACi's, trichostatin and sodium butyrate, promote growth arrest and differentiation with negligible cell death in glioma cells and induce expression of CD81 and cyclin-dependent kinase inhibitor 1A (p21(CIP/WAF-1)), another regulator of cytostasis in astrocytes. Interference RNA knock-down of CD81 abrogates cytostasis promoted by HDAC inhibition indicating that HDACi-induced CD81 is responsible for growth arrest. Induction of CD81 expression through HDAC inhibition is a novel strategy to promote growth arrest in glioma cells.     

VEGF Immunopositivity Related to Malignancy Degree,Proliferative Activity and Angiogenesis in ENU-Induced Gliomas

Growth of solid tumors is highly dependent on angiogenesis. During tumor development, neoplastic cells switch to an angiogenic phenotype, playing a significant role in the expression of the vascular endothelial growth factor (VEGF). Seventy-two brain gliomas were induced in Sprague Dawley rats by prenatal exposure to ethylnitrosourea (ENU). Screening and location of tumors was carried out using magnetic resonance imaging (MRI). Conventional histology and immunocytochemistry for antibodies against glial fibrillary acidic protein (GFAP), S-100, NF, oligodendrocyte Ab-2, Ki-67, and VEGF165 were performed. The proliferation index (PI) was calculated from the Ki-67 labeling index, and the concentration of VEGF165 was quantified by enzyme-linked immunosorbent assay (ELISA). In vivo identification of macro- and microtumor appears to be useful to lead morphological and biochemical studies. Histopathology allows us to identify microtumors as classic oligodendrogliomas (CO; mean PI of 6.01 +/- 2.8%) and macrotumors as anaplastic oligodendrogliomas (AO; mean PI of 14.06 +/- 5%). Classic oligodendrogliomas show scarce VEGF165 expression whereas anaplastic ones display VEGF165 protein level 100-fold increased respect to CO. Astrocytes, neoplastic, and endothelial cells show differential immunostaining patterns from the border to the core of neoplasm. Positive structures for VEGF and their distribution vary according to PI increase. Anaplastic gliomas displaying VEGF-positive intratumor capillaries correspond to the highest PI values. To identify the "angiogenic switch," we propose the glioma stage characterized by VEGF immunopositive neoplastic cells inside the tumor and positive endothelial cells surrounding it.     

骨桥蛋白与胶质瘤关系的研究进展

骨桥蛋白(OPN)是一种分泌型、黏附性的磷酸化糖蛋白,广泛分布于体内多种组织和细胞内。OPN在多种恶性肿瘤组织的表达明显上调。脑胶质瘤是一种低分化瘤,恶性度高,外科手术和其他辅助治疗都无法达到生物学切除或杀灭,残余的肿瘤细胞极易复发。近年来,随着分子生物学的发展及对胶质瘤研究的深入,发现OPN与胶质瘤的发生发展有着十分密切的关系。     

周期蛋白依赖性激酶1在胶质瘤组织中的表达及其沉默对胶质瘤细胞恶性表型的影响

目的探讨周期蛋白依赖性激酶1(CDK1)在胶质瘤组织中的表达及其沉默对胶质瘤细胞恶性表型的影响。方法利用自建的人脑胶质瘤体外细胞系SHG44及其移植瘤组织、脑肿瘤干细胞、神经干细胞、不同恶性程度的胶质瘤手术标本构建组织芯片,免疫组化染色检测其CDK1蛋白表达;应用RNA干扰技术使CDK1在SHG44细胞及其移植瘤组织中沉默,观察其随后发生的表型变化。结果CDK1在临床标本中随胶质瘤恶性程度升高表达强度增加,Ⅰ-Ⅳ级的阳性表达率分别为22.2%、40.0%、69.6%和78.6%(P=0.01)。体外培养的人脑胶质瘤SHG44细胞球体和裸小鼠皮下移植瘤CDK1表达强度均较高,而神经干细胞和脑肿瘤干细胞球体表达强度低,在细胞增殖活性高的人胚胎脑组织和裸小鼠骨髓中CDK1亦高表达,但在正常成人脑组织低表达。C1和C3体外转染SHG44细胞后,将细胞周期阻滞在G2/M期,而且诱导了凋亡,细胞凋亡率分别上升至27.8%和36.5%。CDK1沉默的裸鼠皮下移植瘤瘤重明显降低,细胞凋亡率为57.1%,明显高于对照组(8.5%)。结论CDK1的高表达呵促进胶质瘤的发生和发展,CDK1沉默后的肿瘤细胞恶性表型可得到控制,CDK1可作为胶质瘤病因分子行进一步研究。     

Comparison of numerical change of epidermal growth factor receptor gene among pre- and postradiation glioma,and gliosis,and its clinical use

Surgery with following chemoradiotherapy is the mainstream glioma treatment. In the course of postradiation events, however, it is sometimes difficult for neurosurgeons, radiologists, and pathologists to discriminate tumor recurrence from radiation necrosis. The epidermal growth factor receptor (EGFR) gene, on chromosome 7, is known to gain in copy number frequently in high-grade gliomas. The authors applied the fluorescence in situ hybridization (FISH) method to observe the gene's numerical status in pre- and postradiation glioma samples to elucidate whether this technique is useful in the discrimination of glioma recurrence from radiation necrosis. When 15 postradiation glioma samples and 4 postradiation nonglioma samples were tested, all the recurrent glioma tissue harbored numerical aberrations of the gene, whereas no abnormality could be observed in necrosis or in nonglioma gliosis. FISH could even prove a residual glioma cell in a gliotic tissue taken by needle biopsy after gamma-knife radiosurgery, which had been executed on a supposed metastatic brain tumor. FISH is considered to be of help in accurate diagnosis, especially when the usual histopathological diagnosis is difficult because of radiation effects or small sample size.     

RNA干扰对胶质瘤细胞垂体瘤转化基因影响的实验研究

目的构建表达靶向抑制PTTG基因的表达短发夹结构(shRNA)的RNA干扰载体。方法根据PTTG基因cDNA序列,设计针对PTTG基因的3组干扰序列,并设计1组阴性对照序列,克隆到真核表达载体pGenesil-1中,进行酶切鉴定和测序鉴定。将构建好的4组重组质粒分别命名为PTTG-1组,PTTG-2组,PTTG-3组、阴性对照NC(negativecontrol)组。利用RNA干扰技术,将以上shRNA分别转染细胞中,逆转录聚合酶链式反应(RT-PCR)检测PTTGmRNA表达水平、Western blot检测PTTG蛋白表达水平。结果构建的PTTG RNA干扰序列和阴性对照序列经基因测序证明序列正确。细胞在转染PTTG干扰载体后,提取细胞的总RNA,经RT-PCR电泳发现,在转染24 h后,PTTG-2、PTTG-3即显示出抑制作用,PTTGmRNA表达水平降低,PTTG-1组对目的基因的抑制作用不明显;在转染48 h后,各组均显示出抑制作用,但PTTG-3的抑制作用更明显;转染72 h后,PTTG-1组有微弱的抑制作用,PTTG-2及PTTG-3组仍有显示明显的抑制作用,但PTTG-3抑制作用较PTTG-2更强烈。Western blot检测不同时间PTTG蛋白的变化显示,在转染24 h后,PTTG-1、PTTG-2、PTTG-3组对目的基因的抑制作用均不明显;在转染48 h后,PTTG-1、PTTG-2、PTTG-3组均显示出抑制作用,但PTTG-3的抑制作用更明显;转染h小时后,PTTG-1组没有抑制作用,PTTG-2及PTTG-3组仍有显示明显的抑制作用,但PTTG-3抑制作用较PTTG-2更强烈。结论成功构建了靶向抑制PTTG基因的表达短发夹结构(shRNA)的RNA干扰载体,并筛选了干扰效果最强的序列,为进一步实验打下了基础。